Sorry to hear of your problems kb3pwc. It must be very frustrating. You really to find out what the problem is. Without knowing that, its difficult to know who might be responsible. Note that Yanmars can be a bit hard to start once the weather gets cold because there is no glow plug, so that alone wouldn't worry me. The white smoke is another issue, and I am baffled by the "piston movement" comment. I hope this works out for you.